In recent game machines, a game program is read in from a storage medium such as a DVD-ROM, and a main part of a game is played in response to a user's manipulation. Upon the game program being read in from the storage medium, a title screen representing a title of the game is displayed on a display. Before or after the title screen is displayed, so-called a demonstration image (or opening image) including a digest image of a content of the game is reproduced. Reproduction of the demonstration image and display of the title screen are repeated alternately. When the user performs a predetermined manipulation, the reproduction of the demonstration image or the display of the title screen is cancelled, and the play of the main part of the game is initiated.
If the demonstration image reproduced as described above is, for example, a content in which one or plural kinds of image(s) is/are merely reproduced in repetition, the user who sees this content once will become less interested in the demonstration image. Because of this, when the game is played in repetition, the user may skip reproduction of the demonstration image in the second and the following games. However, for example, if a scene which appears at a time point when the game is played until a last phase of a story is incorporated into a demonstration image in a game having a plot, in order to attract the user's interest, the user who does not start the game yet or has not proceeded to the last phase of the story, will previously know the scene or a character which does not appear in the present state of proceeding of the game performed by that user. This may cause some problems in the proceeding of the game, for example, the user may lose the interest in the game.
To avoid this, Patent Literature 1, Patent Literature 2, and the like disclose proposals for changing the demonstration image. Patent Literature 1 discloses a game in which the user manipulates a player character to make a battle with a character selected from another plural characters, in a game machine provided in a game center, etc. In this game, plural movies are joined together to construct a demonstration image, and this demonstration image is reproduced while the game is not being played. A movie which is a portion of the demonstration image is changed to include an image of a character which frequently made a battle with the player character in the past games.
Patent Literature 2 discloses that a mechanical activation time of the game machine is counted, and a demonstration image is changed according to the counted time. More specifically, during a time period in which the counted time does not exceed a predetermined threshold (switching time), the demonstration image relating to a front half portion in the proceeding of the game is reproduced. After the counted time exceeds the predetermined threshold, the demonstration image relating to a rear half portion in the proceeding of the game is reproduced instead of the previous demonstration image.